Plate fob securing chords



FRANCIS C. LOYVTHORP, OF TRENTON, NEW' JERSEY.

PLATEFOR SECURING- CHORDS, BRACES, 85o., OF TRUSS-BRIDG-ES, &G.

Specicatioii of Letters Patent No. 27,457, dated March 13, 1860.

To all whom it may concern:

Be it known that LFRAN ois C. Lowri-IORP, of Trenton, in the county ofMercer and State of New Jersey, have invented a new and usefulImprovement iii Bridges; and I do hereby declare the following to be afull, clear, and exact description of the saine, reference being had tothe accompanying drawing and to the letters of reference marked thereon.

My invention consists of a combination plate with open slots adapted toreceive, and arranged in respect to, the enlarged ends of lower chordrods and also arranged to receive the verticals and diagoiials of atruss frame or other bridge substantially as described hereafter.

The object of my invention is to facilitate the erection of the bridge,and to afford a secure attachment for the chord rods to the combinationplate, without the necessity of the expensive forging and machine workemployed on the lower chords of other bridges.

In order to enable others skilled in the art to make and use myinvention will now proceed to describe its construction and operation.

On reference to the accompanyingl drawing which forms a part of thisspecification Figure l, is a side view of sufficient of an iron trussframe bridge to illustrate my im provement. Fig. Q, a transverse sectionof part of the bridge. Fig. 3, a section on the line l, 2 Fig. 2. Fig.4L a section on the line 3 4 Fig. l. Fig. 5 a plan view, and Figs. (Sand 7, and S, views illustrating a modified plan of securing thediagonals to the combination plate.

Similar letters refer to similar throughout the several views.

On reference to Figs. l, 2, 3, 4t and 5, A represents one of thecombination plates, B and B the ends of two transverse or floor beamsresting on the lugs a. a of the plate, C one of the vertical posts, Dand D the diagonals, E the horizontal diagonals, and Gr G and G G, thelower chord rods of an iron truss frame bridge.

The diagonals D D pass directly through openings in the body and nearthe middle of the combination plate on which are cast inclinedprojections o b forming bearings for the nuts 7iv It, the latter beingscrewed onto the ends of the diagonals, serve to connect the latter tothe combination plate.

The horizontal diagonals E E pass parts through inclined openings in thebody of the same plate and are secured to the latter by nuts which bearagainst the inclined surfaces on the end c of said plate, as bestobserved on reference to Fig.

The lower chord rods G and G consist of plain square bars of wroughtiron set up at the opposite ends so as to form the enlargements or Theads illustrated in the drawing.

Slots are formed on the opposite ends of the combination plate, eachslot being large enough to admit the ends of two adjacent rods which areconnected to the plate by simply sliding them laterally into the slots,the T heads of one set of rods G bearing on one side of the plate,'andthe T heads of the adjacent rods, on the opposite side of the sameplate. Small lips e c Fig. 2, cast on the opposite ends of the plateserve to retain the ends of the rods in their proper position within theslots.

It will be readily seen that the enlarged ends of the rods formed bybeating or setting up the latter when heated, will afford the mostsubstantial and secure medium for resisting the strain imparted to thelower chord rods, that but little manual labor is required for formingthese enlargeineuts, that the small amount of forged work demanded hasno tendency to deteriorate the metal, but on the contrary to make itmore compact and safe, and that in the above respects the manner ofconstructing and fastening the chords is much superior to the ordinaryriveted attachments, to the link arrangement adopted in whaty is knownas the Vhipple bridge, as well as to the nut and screw plan adopted iiithe patent granted to me on the 30th day of June 1857 inasmuch as theriveting requires tedious and laborious manipulation, and the links anumber of weldings, the nut and screw arrangement requiring expensiveforged as well as machine work. It will also be seen that the open slotsof the coinbination plate and enlarged ends of the rods afford thosefacilities for ready erection of the bridge which are not presented byany of the usual modes of constructing and attaching lower chord rods.

The views, Figs. 6, 7 and 8, illustrate a mode of connecting thediagonals to the conibination plate by mea-ns of lenlarged or T heads,instead of screw nuts. 'Vhen this plan is adopted an opening is formedin the combination plate large enough to admit the ends of the Whole ofthe diagonale Which have to be connected to the said plate, the openingbeing larger in the middle than at the ends.

The enlarged ends of the diagonale D D are inserted Aone after the otherinto the middle of the opening and then moved laterally so as to lit oneinto one end and the other into the other end of the opening thediagonal D is then inserted into the middle of the opening and itsprojecting end turned around, so that when drawn tight its shoulders maycatch against the plate as seen in Fig. 7. By this arrangement thediagonal D serves to maintain the diagonale D D in their properposition.

Although I have illustrated and described a slotted combination platefor receiving the ends of eight chord rods, it Will be evident that aplate may be so modified as to be adapted to the reception of more orless than this number of rods. It Will also be seen that my improvementis applicable to suspension bridges and other structures in whichdiagonals, verticals, chord rods and combination plates are used.

I claim as my invention and desire to secure by Letters Patent- Thecombination plate A with open slots adapted to receive and arranged inrespect to the enlarged endsof the chord rods G and G', and alsoarranged to receive the verticals and dagonals of a truss frame or otherbridge substantially as and for the purpose herein set forth.

In testimony whereof, I have signed my name to this specification in thepresence of two subscribing Witnesses.

F. C. LOWTHORP.

Witnesses HENRY HowsoN, CHARLES D. FREEMAN.

